CN103943617B - Light-emitting device and its manufacturing method - Google Patents

Abstract

The light emitting device (100) comprises: a base (50); a semiconductor light emitting element (10) mounted on the base (50); a frame (20) surrounding the semiconductor light emitting element (10) on the base (50); filling A resin molded layer (30) made of resin within the frame body (20). The frame body (20) includes: a first frame (21); and a second frame (22) formed on the upper surface of the first frame (21). The resin molded layer (30) includes: a first resin molded layer (31) formed at approximately the same height as the top of the first frame (21) and embedded with a semiconductor light emitting element (10); The upper surface of the molded layer (31), the second resin molded layer (32) formed to a height approximately equal to the top of the second frame (22), on the first resin molded layer (31) or the second resin molded layer (31) At least one of the layers (32) includes a wavelength converting member for converting the wavelength of light emitted from the semiconductor light emitting element (10).

Description

Light emitting device and manufacturing method thereof

technical field

The present invention relates to a light-emitting device including a semiconductor light-emitting element such as a light-emitting diode and a method for manufacturing the same.

Background technique

In recent years, light-emitting diodes (Light Emitting Diode: hereinafter also referred to as "LED"), which consume less power instead of conventional incandescent lamps, are being used in lamps for general lighting. is expanding. Among them, in spotlights, searchlights, etc., in order to improve the light extraction efficiency of the secondary optical system, LEDs with high output and high light quality with as small a light emitting part as possible, and less uneven brightness and hue within the light emitting surface are desired.

As a method of reducing such uneven light emission, there is a method of blending a filler in a sealing material of a light-emitting element to diffuse light. For example, in order to realize a white LED, an example of a light-emitting device that combines a blue LED and a YAG phosphor that emits yellow fluorescence when excited by light emitted from the blue LED is conceivable. In this light-emitting device, a YAG phosphor is blended in a sealing material such as resin for sealing the blue LED mounted in the cover. Furthermore, by mixing not only the phosphor but also the diffusing material in the same sealing material, the phosphor is further dispersed in the sealing resin.

However, in such a structure, color unevenness often occurs. Specifically, regarding the emitted light emitted from the LED element, when focusing on the length of the optical path between the light-emitting device and the distance from the light-emitting surface, the light emitted from directly above the LED element and the light emitted from the LED element to the A difference in optical path length occurs in light emitted obliquely and passing through the sealing material. As a result, the longer the optical path length, the more components that excite the phosphor dispersed in the sealing resin, so that the color tone varies. Therefore, when the light-emitting surface of the light-emitting device is viewed in a plan view, ring-shaped unevenness of hue occurs around the light-emitting surface.

refer to:

Japanese Patent Laid-Open No. 2008-041290:

Japanese Patent Laid-Open No. 2008-282754;

Japanese Patent Laid-Open No. 2011-159970

Contents of the invention

The present invention is made in order to solve existing such problems. The main object of the present invention is to provide a light-emitting device and a manufacturing method thereof that can suppress color unevenness and improve the quality of output light.

In order to achieve the above object, according to the light emitting device according to one aspect of the present invention, there can be provided a light emitting device comprising: a base; a semiconductor light emitting element mounted on the base; A frame around the light-emitting element; a resin molded layer filled in the frame, the frame comprising: a first frame; a second frame formed on the upper surface of the first frame, the resin molded The layers include: a first resin molded layer formed at approximately the same height as the top of the first frame and embedded with the semiconductor light emitting element; a second resin molded layer laminated on the first resin molded layer. The upper surface of the molded layer is formed to be approximately equal to the height of the top of the second frame, and at least one of the first resin molded layer or the second resin molded layer contains a A wavelength conversion member for converting the wavelength of light emitted from the semiconductor light emitting element. According to the above configuration, the thickness of the first resin mold layer is made substantially uniform, and high-quality light emission with suppressed color unevenness of output light can be obtained.

In addition, according to the method of manufacturing a light emitting device according to another aspect of the present invention, it is possible to provide a method of manufacturing a light emitting device comprising: a base; a semiconductor light emitting element mounted on the base; A frame surrounding the semiconductor light-emitting element; a resin molding layer filled in the sealing area defined by the frame; the manufacturing method of the light-emitting device includes: forming a first Frame process: In the sealing area inside the first frame, the first molding resin is filled to a height equal to the height of the first molding resin to seal the semiconductor light emitting element installed in the sealing area A step in which the top of the first frame is substantially aligned; a step of forming a second frame so as to cover at least a part of the first frame after hardening the first molding resin to form a first resin mold layer; The inside of the second frame is filled with the second molding resin so that the height of the second molding resin is substantially consistent with the top of the second frame; the second molding resin is hardened to form a second resin mold The process of layer formation (32). According to the above configuration, it is easy to laminate the first molding resin with a substantially uniform thickness, and it is possible to obtain high-quality light emission with suppressed color unevenness of output light.

Furthermore, according to the method of manufacturing a light-emitting device according to another aspect of the present invention, there is provided a method of manufacturing a light-emitting device including: preparing a base in which a conductive member is arranged on an insulating plane; a process of installing a semiconductor light emitting element in a manner electrically connected to the conductive member, and forming a first frame around the semiconductor light emitting element; forming a first resin mold in a region defined by the first frame a step of forming a layer; a step of forming a second frame on the upper surface of the first frame; and a step of forming a second resin molded layer in an area defined by the second frame. According to the above configuration, it is easy to laminate the first molding resin with a substantially uniform thickness, and it is possible to obtain high-quality light emission with suppressed color unevenness of output light.

The above and other objects of the present invention and features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a plan view showing a light emitting device according to Embodiment 1 of the present invention.

Fig. 2 is a sectional view taken along line II-II of Fig. 1 .

Fig. 3 is a sectional perspective view taken along line III-III of Fig. 1 .

4A to 4D are schematic cross-sectional views showing manufacturing steps of the light emitting device of FIG. 1 .

5 is a schematic cross-sectional view showing a light emitting device according to a modified example.

Fig. 6 is a cross-sectional view of a light emitting device according to another modification.

Fig. 7 is a cross-sectional view of a light emitting device according to another modification.

Fig. 8 is a schematic cross-sectional view showing a light emitting device according to another modified example.

Fig. 9 is an enlarged sectional view of main parts of the light emitting device shown in Fig. 2 .

10 is an enlarged cross-sectional view of main parts of a light emitting device according to a modification.

Fig. 11 is a schematic cross-sectional view showing a state where a protective element is embedded with a high-viscosity resin.

Fig. 12 is a plan view of a light emitting device according to another modification.

FIG. 13 is a schematic cross-sectional view showing a light emitting device according to Example 2. FIG.

Fig. 14 is a cross-sectional view showing a conventional light emitting device.

Fig. 15 is an enlarged cross-sectional view showing the interface between the housing and the resin mold layer of the light-emitting device of Fig. 14 .

Detailed ways

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments shown below are examples showing the light emitting device and its manufacturing method for realizing the technical idea of the present invention, and the present invention does not limit the light emitting device and its manufacturing method to the following. In addition, this specification does not limit the member shown in a claim to the member of embodiment. Dimensions, materials, shapes, relative arrangements, and the like of components described in the embodiments do not limit the scope of the present invention thereto unless specifically described, and are merely illustrative examples. In addition, the size, positional relationship, etc. of the members shown in each drawing are exaggerated for clarification of description. Furthermore, in the following description, the same names and symbols refer to the same or homogeneous members, and detailed descriptions are appropriately omitted. Furthermore, each element constituting the present invention may be implemented in such a way that the same member constitutes a plurality of elements and one member also serves as a plurality of elements, or vice versa, a plurality of members may share the function of one member. In addition, the contents described in some of the examples and embodiments can also be used in other examples, embodiments, and the like.

In the light-emitting device according to one embodiment of the present invention, the base has an insulating plane, a conductive member is formed on the insulating plane, and the conductive member is electrically connected to the semiconductor light-emitting element. .

In addition, in the light-emitting device according to another embodiment of the present invention, the first resin mold layer may include a wavelength conversion member for converting the wavelength of light emitted from the semiconductor light-emitting element.

Furthermore, in the light-emitting device according to another embodiment of the present invention, the second resin mold layer may include a diffusing material for diffusing the emitted light from the semiconductor light-emitting element. According to the above configuration, the sealing resin can be separated into a first resin mold layer for wavelength conversion by mixing a wavelength conversion member such as a phosphor and a second resin mold layer for reducing uneven light emission by mixing a diffusing agent. Obtain a light emitting device with higher light quality.

Furthermore, in the light-emitting device according to another embodiment of the present invention, the boundary position between the lower end of the inner surface of the first frame and the base body may be arranged at a lower end than the lower end of the inner surface of the second frame. the inside of the frame. According to the above configuration, the inner surface side of the housing is formed in an inclined shape as a whole, so that the light extraction efficiency can be improved. In addition, it is also possible to avoid a situation where the second frame partially covers the upper portion of the first resin mold layer 31 to prevent light extraction.

Furthermore, in the light emitting device according to another embodiment of the present invention, the second frame may cover the upper surface and the outer surface of the first frame. According to the above configuration, the frame body can be formed so that the second frame covers the first frame, and the frame body can be increased in size, and the bonding strength at the time of fixing to the base can be improved to improve reliability.

Furthermore, in the light emitting device according to another embodiment of the present invention, the second frame may be formed thicker than the first frame in plan view. According to the above configuration, the frame body can be formed so that the upper surface and the outer surface of the first frame are covered by the second frame, the frame body can be enlarged, and the bonding strength at the time of fixing to the base can be increased to improve reliability.

In addition, in the light-emitting device according to another embodiment of the present invention, the viscosity of the resin for the first frame forming the first frame may be higher than the viscosity of the resin for the second frame forming the second frame. . According to the above configuration, the first frame can be easily formed narrow and tall.

Furthermore, the light emitting device according to another embodiment of the present invention may further include a protection element connected in antiparallel to the semiconductor light emitting element, and the protection element may be embedded in the second frame. According to the above structure, the viscosity of the resin for the second frame in which the protective element is embedded can be reduced, and a situation in which a gap is generated at the interface between the surface of the protective element and the resin for the second frame after embedding of the resin for the second frame can be avoided, thereby improving Reliability of light emitting devices.

Furthermore, in the light emitting device according to another embodiment of the present invention, the height of the central region of the second resin mold layer may be formed to be substantially the same height as the top of the second frame. According to the above configuration, the thicknesses of the first resin molded layer and the second resin molded layer can be kept substantially constant even in the vicinity of the housing, thereby suppressing light emission near the housing where color unevenness has conventionally easily occurred. The effect of uneven hue of the color.

Furthermore, in the light emitting device according to another embodiment of the present invention, the height of the central region of the second resin mold layer may be formed higher than the top of the second frame. According to the above structure, the effect of improving the luminous flux by the second resin mold layer is obtained.

In addition, in the light-emitting device according to another embodiment of the present invention, the wavelength conversion member may be a phosphor that can be excited by light emitted from the semiconductor light-emitting element.

Furthermore, in the light-emitting device according to another embodiment of the present invention, the first resin mold layer may include a phosphor layer and a translucent resin layer formed on the phosphor layer. According to the above configuration, the phosphor can be deposited in the first resin mold layer to efficiently capture light from the semiconductor light emitting element, thereby facilitating wavelength conversion.

(Example 1)

FIG. 1 shows a top view of a light emitting device 100 according to Embodiment 1 of the present invention, FIG. 2 shows a cross-sectional view along line II-II, and shows a perspective cross-sectional view along line III-III in FIG. 3 . In addition, the light emitting device The manufacturing process of 100 is shown in the schematic cross-sectional views of FIGS. 4A to 4D , respectively. The light emitting device 100 shown in these drawings includes: a base 50; a semiconductor light emitting element 10 mounted on the base 50; a resin frame 20 disposed on the base 50 so as to surround the semiconductor light emitting element 10; The resin mold layer 30 made of resin in the sealing area SA defined by the frame body 20 .

The base has an insulating plane, and a conductive member is formed on the insulating plane. Wiring is performed by electrically connecting the conductive member to the semiconductor light emitting element.

Here, the base body 50 is formed in a rectangular shape, and the frame body 20 is also formed in a rectangular shape. One or more semiconductor light emitting elements 10 are mounted in the sealing area SA surrounded by the frame body 20 . Here, in the rectangular sealing area SA, a plurality of semiconductor light emitting elements 10 are arranged in a matrix. In this example, 6 vertical x 6 horizontal = 36 semiconductor light emitting elements in total are mounted. However, the number and arrangement pattern of semiconductor light emitting elements may be arbitrary. For example, they may be arranged in a rectangular shape in which the number of vertical and horizontal objects is changed, or in a circular shape or a polygonal shape. Furthermore, one semiconductor light emitting element 10 may be provided as in the light emitting device 100B shown in the modified example of FIG. 5 . (semiconductor light emitting element 10)

As the semiconductor light emitting element 10, a light emitting diode, a semiconductor laser, or the like can be used. Such a semiconductor light-emitting element 10 is suitably made of ZnS, SiC, GaN, GaP, InN, AlN, ZnSe, GaAsP, GaAlAs, InGaN, GaAlN, AlInGaP, AlInGaN, etc. on a substrate by liquid phase growth method, HDVPE method, or MOCVD method. A structure in which a semiconductor is used as a light-emitting layer. The emission wavelengths of various semiconductor light emitting elements can be selected from ultraviolet light to infrared light by selecting the material of the semiconductor layer and its degree of crystal mixing. In particular, a light-emitting element capable of emitting light with high luminance is required to form a display device that can be suitably used outdoors. In contrast, nitride semiconductors are preferable as materials for light-emitting elements that emit green and blue high-intensity light. For example, In _X Al _Y Ga _1-XY N (0≤X≤1, 0≤Y≤1, X+Y≤1) or the like can be used as a material of the light emitting layer. Also, a light emitting element may be formed by combining such a light emitting element and various phosphors 36 (details will be described later) that emit light having a wavelength different from the light emission wavelength of the light emitting element when excited by the light emission. As a material for a light-emitting element emitting red light, a gallium-aluminum-arsenic-based semiconductor or an aluminum-indium-gallium-phosphonium-based semiconductor is preferable. It should be noted that, in order to form a color display device, it is preferable to combine LED chips with a red emission wavelength of 610 nm to 700 nm, a green emission wavelength of 495 nm to 565 nm, and a blue emission wavelength of 430 nm to 490 nm.

In addition, this semiconductor light emitting element 10 is arranged so that the electrode forming surface faces the base body 50, and is mounted using bumps, solder balls, etc., and is formed as an upside-down mounting (so-called flip-mount) in which the back side of the electrode forming surface is the main light extraction surface. flip-chip mounting). However, it is not limited to this configuration, and may be a front mounting type in which the electrode formation surface side opposite to the mounting surface side for mounting to the base is used as the main light extraction surface.

(protection element 12)

In addition, it is preferable that a protective element 12 is connected to the semiconductor light emitting element 10 . The protection element 12 prevents the semiconductor light emitting element 10 from being damaged when a reverse voltage is applied. As such a protective element 12 , a Zener diode or the like connected in parallel in a direction opposite to the conduction direction of the light emitting element can be suitably used. Alternatively, a variable resistor or the like may be used as the protection element 12 . The protective element 12 and the wiring pattern applied to the base body 50 are embedded in a frame body 20 described later. Thereby, the protective element 12 and the wiring pattern can be protected by the frame body 20 without separately covering the protective element 12 and the wiring pattern with a protective film or the like. That is, the frame body 20 can also be used as a protective film that protects the element 12 and the wiring pattern. (substrate 50)

As the base body 50 , an insulating substrate excellent in heat dissipation can be suitably used. For example, a ceramic substrate, in this example an alumina ceramic substrate, can be used. In addition, a glass epoxy resin substrate, an aluminum nitride substrate, or the like can also be appropriately used. As shown in the plan view of FIG. 1 , a frame body 20 defining the sealing area SA is formed substantially in the center of the base body 50 , and external connection terminals 14 for electrical connection to the outside are formed outside the frame body 20 . The external connection terminals 14 are formed as a pair for positive and negative electrodes, and each external connection terminal 14 is electrically connected to the semiconductor light emitting element 10 (and the protective element 12 ) mounted in the sealing area SA through a wiring pattern. In the example of FIG. 1 , positive-side external connection terminals and negative-side external connection terminals are respectively formed by printing on diagonal lines of the rectangular frame body 20 . Here, a pair of external connection terminals is used, but the external connection terminals are not limited to one pair, and may be two or more pairs.

(resin molded layer 30)

The resin molded layer 30 includes: a first resin molded layer 31 ; and a second resin molded layer 32 laminated on the upper surface of the first resin molded layer 31 . The first resin mold layer 31 includes a wavelength conversion member to embed the semiconductor light emitting element 10 . In addition, the second resin mold layer 32 contains a diffusing material to diffuse and mix the light emitted by the semiconductor light emitting element 10 and the light whose wavelength has been converted by the wavelength conversion member, thereby obtaining uniform output light.

(frame 20)

Furthermore, the frame body 20 includes: a first frame 21 made of a resin for a first frame body; and a second frame 22 made of a resin for a second frame body. In this way, the first resin mold layer 31 and the second resin mold layer 32 can be easily laminated with a substantially uniform thickness, and high-quality light emission can be obtained with suppressed color unevenness of the output light (details will be described later). .

(first resin molded layer 31)

As shown in the cross-sectional view of FIG. 2 , the first resin mold layer 31 includes: a wavelength conversion layer 34 ; and a translucent resin layer 35 formed on the wavelength conversion layer 34 . Therefore, when the first resin mold layer 31 is formed, the first mold resin for the first resin mold layer 31 contains a wavelength conversion member in the translucent resin. When the first molded resin is filled into the first frame 21, the wavelength conversion member contained in the translucent resin settles due to its own weight, and the wavelength conversion member located below the first resin molded layer 31 The wavelength conversion layer 34 is formed, and a light-transmitting resin layer 35 having fewer wavelength conversion members is formed on the first resin mold layer 31 . With such a configuration, the wavelength conversion member can be efficiently disposed around and on the upper surface of the semiconductor light emitting element 10 , and the wavelength of light emitted by the semiconductor light emitting element 10 can be efficiently converted. As the translucent resin constituting such a first molding resin, a silicone resin or the like can be suitably used.

(Phosphor 36)

As such a wavelength converting member, phosphor 36 that can be excited by light emitted from semiconductor light emitting element 10 can be suitably used. As the fluorescent substance 36, YAG, CASN, SCASN, etc. can be used suitably. For example, by using an InGaN LED for the semiconductor light-emitting element 10 and using YAG activated with a rare earth element for the phosphor 36, blue light of the LED and yellow fluorescence after wavelength conversion by exciting the phosphor with the blue light can be obtained. , to obtain white light by color mixing of these lights. Thereby, a white light-emitting device can be obtained. In addition, a plurality of types of phosphors may be mixed as needed. For example, by adding a red-based phosphor, it is possible to obtain a warm-colored luminescent color with a red component added thereto. In addition, emission colors other than white light can also be obtained. Here, the peak wavelength of the light-emitting diode is set to blue at 445 to 455 nm, and YAG, which is excited by the blue light to emit yellow fluorescence, LAG, which emits yellow-green fluorescence, and SCASN, which emits red fluorescence, are combined with the phosphor to obtain A light emitting device that mixes the colors of these lights to generate white light of the color of an incandescent lamp as output light.

Phosphor 36 may be distributed downward in first resin mold layer 31 . Accordingly, by arranging the phosphor 36 near the semiconductor light emitting element 10 , the emitted light emitted from the semiconductor light emitting element 10 can be efficiently irradiated to the phosphor 36 to perform wavelength conversion. In order to bias the phosphor 36 as described above, for example, the first resin mold layer 31 is filled with the phosphor 36 in a state where it is mixed, and in the stage of hardening the first resin mold layer 31, the phosphor is 36 is naturally settled by its own weight. As a result, a region containing a large amount of phosphors 36 is formed under the cured first resin mold layer 31 .

In the example of the light-emitting device 100 shown in FIG. 2 , the first resin mold layer 31 is divided into the wavelength converting layer 34 containing the phosphor and the translucent resin layer not containing the phosphor 36 for explanation. 35, but actually the boundary between the wavelength conversion layer 34 and the translucent resin layer 35 is blurred. The state of precipitation of the phosphor also varies depending on the viscosity of the first molding resin used or the particle diameter, specific gravity, and the like of the phosphor. Therefore, the present invention also includes the state that the density of the phosphor 36 becomes higher as it goes below the first resin mold layer 31 , and vice versa, as in the light emitting device 100E shown as a modified example in FIG. 8 . Upward, the state in which the density of the phosphor 36 is lower. The first resin mold layer 31 is composed of a wavelength converting layer 34 in which a phosphor 36 is deposited, and a translucent resin layer 35 substantially not containing the phosphor 36 . In this specification, the term "substantially not containing phosphor" naturally includes the case where phosphor particles are not contained at all, and also includes cases where phosphor particles are contained in a small amount but light emitted from the semiconductor light emitting element is not confirmed. Absorption situation.

(Second resin molded layer 32)

The second resin molded layer 32 is formed on the upper surface of the first resin molded layer 31 . The second resin molded layer 32 contains a diffusion material. Thereby, the emitted light from the LED and the fluorescent light after the wavelength conversion of the emitted light by the phosphor 36 are diffused by the second resin mold layer 32 to obtain uniform light. As such a second molding resin, a silicone resin or the like can be suitably used. In addition, a filler can be used as a diffusing material. In Example 1, a dimethyl silicone resin was used as the second molding resin, and TiO ₂ powder was mixed as a filler in the resin.

In this way, part of the first resin mold layer 31 functions as the wavelength conversion layer 34 for converting the wavelength of light emitted from the semiconductor light emitting element 10, while the second resin mold layer 32 functions as the 10 functions as a diffusion layer that diffuses the emitted light and the wavelength-converted light to uniformly mix colors. In this way, by dividing the resin mold layer 30 into two layers and assigning the wavelength conversion function and the diffusion function to each layer, each layer can be effectively utilized to exert independent functions, thereby obtaining uniform light emission.

Here, it is preferable that the upper surface of the first resin molded layer 31 is formed in substantially the same plane as the top of the first frame 21 . As shown in FIG. 4A and FIG. 4B , after the first frame 21 is formed, when the first resin mold layer 31 is formed and the first mold resin is filled into the first frame 21, the first mold This is achieved by filling the resin so that it becomes approximately the same surface as the top of the first frame 21 . That is, in the conventional method, if the molding resin is filled into the frame body 20 in two stages, as shown in FIG. As a result, a state in which the first molding resin rises occurs in the vicinity of the frame body 920 due to surface tension. When the second molding resin is filled after such first molding resin hardens, as shown in FIG. The amount by which the resin molded layer 931 becomes thicker results in that the diffusion effect of light by the second resin molded layer 932 is weak, and especially the output light is generated annularly at a portion around the resin molded layer. Uneven hue.

In contrast, in the light-emitting device 100 according to the first embodiment, by stacking the housings 20 in two stages, the influence of the above-mentioned surface tension is reduced, and the upward extension of the first molding resin is avoided. That is, first, as shown in FIG. 4A , the first frame 21 having a height corresponding to the thickness of the first resin molded layer 31 is formed. Thereby, when filling the first resin molded layer 31 into the sealing area SA as shown in FIG. The entire area of the sealing area SA including the vicinity of the first frame 21 is formed to have a substantially uniform thickness. And, as shown in FIG. 4C, by forming the second frame 22 after the hardening of the first resin mold layer 31, the frame body 20 of a desired height can be obtained, and the second resin mold can be formed as shown in FIG. 4D. By forming the layer 32, the film thicknesses of the plurality of resin molded layers can be made uniform and color unevenness can be suppressed.

In this way, the thicknesses of the first resin molded layer 31 and the second resin molded layer 32 can be kept substantially constant even in the vicinity of the frame body 20, thereby suppressing light emission in the vicinity of the frame body 20, which has been prone to color unevenness in the past. The hue of the color is uneven.

In this specification, the so-called "top" does not mean the highest position of the frame, but means that when the molded resin is filled into the sealing area defined by the frame, the height of the liquid surface of the molded resin is approximately The part that is consistent and does not substantially produce upward extension. In other words, it refers to the height of the portion that demarcates the area filled with molded resin, and is at a position that has nothing to do with the filling of such molded resin, such as a position away from the sealing area on the outer surface of the frame. A mode that protrudes upward is also included in the invention of the present application.

In addition, the upper surface of the 2nd resin mold layer 32 is made into a planar shape in the example of FIG. 2 etc. FIG. In other words, the height of the second resin molded layer 32 is formed to be substantially the same height as the top of the second frame 22 from the edge to the central region. However, the present invention is not limited to this configuration. For example, the upper surface of the second resin mold layer 32 may be formed such that the height of the central region is higher than the top of the second frame 22 . Such an example is shown in the sectional view of FIG. 7 as a modified example. This light emitting device 100D is formed in a shape in which the upper surface of the second resin mold layer 32D is convexly curved in a central region. In this way, the loss caused by the total reflection of the output light at the interface with the air can be reduced, and the luminous flux (beam) can be improved.

(frame 20)

Next, the frame body 20 will be described. The frame body 20 is preferably formed of a white-based resin in order to increase the reflectance. In addition, in order to facilitate formation on the base body 50 , it is formed in a dome shape in cross-sectional view. In particular, it is preferable to form an inclined surface that expands upward to widen the opening area on the inner surface side of the sealing area SA so that the output light is reflected and extracted upward.

In addition, the frame body 20 is formed of a first frame 21 and a second frame 22 . The first frame 21 is formed on the base body 50 to define the sealing area SA surrounding the semiconductor light emitting element 10 . The first molding resin is installed in the sealing area SA defined by the first frame 21 . In this way, the first frame 21 is used as a bank filled with the first molding resin. As the resin for the first frame constituting such first frame 21 , a resin that is excellent in adhesiveness to the base body 50 and also excellent in adhesiveness to the first molding resin can be used. As such a resin for the first frame, silicone resin, epoxy resin, or the like can be suitably used. (second box 22)

The second frame 22 is formed on the upper surface of the first frame 21 and serves as a bank for filling the upper surface of the first resin mold layer 31 obtained by curing the first mold resin with the second mold resin. Therefore, the second frame body resin forming the second frame 22 can be selected from a resin that is excellent in adhesion to the first frame 21 and also excellent in adhesion to the second molding resin. It is preferable to use the same kind of resin as the resin for the first frame. Among them, it is preferable to make the viscosity lower than that of the resin for the first frame (details will be described later). As such a resin for the second frame, silicone resin, epoxy resin, or the like can be suitably used. In addition, the second frame 22 is formed thicker than the first frame 21 in a plan view, and is laminated so as to cover the area shown by the upper surface and the outer surface of the first frame 21 as shown in FIGS. 4B and 4C . .

As described above, since the second frame 22 is laminated from the upper surface to the outer surface, compared with the light emitting device 100E according to the modified example shown in FIG. The opening part in 20 is easy to form moderate inclined surface. By inclining the opening portion, the light emitted from the semiconductor light emitting element 10 is reflected by the inclined surface to be easily extracted to the outside, thereby improving the light extraction efficiency.

In addition, it is preferable that the interface between the first frame 21 and the second frame 22 is continuously formed. In this way, it is possible to suppress a change in film thickness of the first resin mold layer 31 and the second resin mold layer 32 at the interface between the first frame 21 and the second frame 22 , thereby obtaining high-quality output light.

At this time, it is preferable that, as shown in the enlarged sectional view of FIG. 9 , the boundary portion of the second frame 22 is continuous with the interface between the first frame 21 and the first molding layer. That is, it is preferable that the position _x2 of the end surface of the second frame 22 is slightly shifted to the outside of the frame body 20 from the position _x1 of the end surface of the first frame 21 . In this way, it is possible to avoid the position x ₂ of the end surface of the second frame 22 from covering the first resin mold layer 31 , thereby avoiding loss of light. In addition, by inclining the inner surface side of the housing 20 , it is possible to easily reflect the output light from the portion in the light extraction direction.

At this time, if the second frame 22 is stacked only on the upper surface of the first frame 21 as shown in FIG. The contact area is limited and the bonding strength becomes weak. In contrast, as shown in FIGS. 2 and 4C , etc., the first frame 21 is made wider than the second frame 22 , and the second frame 22 is stacked so that the exposed portion of the first frame 21 is covered. Thereby, the second frame 22 can be fixed to the base body 50 over a wider area, thereby improving the bonding strength and improving the reliability.

In addition, at this time, it is preferable to embed the protective element 12 with resin for the second frame body constituting the second frame 22 . Here, by making the viscosity of the resin for the second frame body lower than that of the resin for the first frame body, the protection element 12 can be reliably embedded and protected in the frame body 20 . In other words, by making the viscosity of the resin for the first frame body higher than that of the resin for the second frame body, the viscosity of the resin for the second frame body constituting the second frame 22 is relatively soft, thereby utilizing the second frame body. The resin for the body can easily make the resin for the second frame follow the surface shape of the protective element 12, thereby improving the reliability of embedding (details will be described later).

It should be noted that, in the present invention, like the light-emitting device according to the modified example shown in the enlarged cross-sectional view of FIG. The structure of the edge of layer 31. In other words, the position _x2 of the edge of the second frame 22 may be formed to be more sealed than the position _x3 of the boundary portion with the first resin molded layer 31 at the opening end of the first frame 21. A structure in which the inner surface side of the area SA is offset. In this case, although the loss of output light corresponding to the amount of the area where the second frame 22 covers the edge of the first resin mold layer 31 occurs, the width of the frame body can be suppressed and the size can be reduced. By reducing the opening area of the sealing area SA, there is an advantage that the light-collecting easiness of the secondary optical system can be improved.

(viscosity of resin)

The viscosity of each frame body resin can be adjusted to an appropriate value by changing the compounding ratio of the materials constituting the resin. Here, dimethyl silicone was used for both the resin for the first frame and the resin for the second frame, and the viscosity was adjusted by changing the compounding ratio of the high-viscosity resin and the low-viscosity resin.

Here, since the first resin for the frame has a high viscosity, it can be formed in a required height and in a narrow width. Since the housing 20 is a region that does not contribute to light emission, it can be said that it is desired to be as narrow as possible from the viewpoint of device miniaturization. However, if the protective element is embedded with a high-viscosity resin, it is difficult to completely fill the fine gaps around the protective element with the resin due to low fluidity. For example, as shown in FIG. 11 , when resin 720 is filled into the upper surface of protective element 12 mounted on base 750 , gap GP may be generated around protective element 12 between base 750 and resin 720 . When such a gap GP is formed, outside air is likely to enter, and there is a concern that a problem may occur due to the entry of moisture or corrosive gas contained in the outside air.

In contrast, by embedding the protective element 12 with the second frame resin and making the viscosity of the second frame resin lower than that of the first frame resin, the protective element is reliably covered with the second frame resin. 12, so that the structure of embedding the protection element 12 in the second frame 22 can be realized. According to this configuration, the viscosity of the first frame 21 can be increased to narrow the width of the first frame 21 , while the second frame 22 can be used to embed the protective element 12 with a reduced gap. In addition, by forming the first frame 21 narrow, the exposed portion of the first frame 21 can be easily covered by the second frame 22 and the overall width of the frame body 20 can be suppressed.

It should be noted that the present invention is not limited to the structure shown in FIG. 2 , and the upper surfaces of the first frames 21C, 21E may also Frame bodies 20C, 20E are formed by laminating second frames 22C, 22E. In particular, the configurations shown in FIGS. 8 and 6 can be suitably used in applications where the width of the housing is further narrowed to achieve miniaturization.

In addition, in the above example, the frame body 20 is formed in a square shape in plan view as shown in FIG. , may be a polygonal shape such as a hexagon or an octagon, or may have corners chamfered, or may be an orbital shape, or may be a shape of an arbitrary closed curved surface such as a circle or an ellipse. It can be designed according to the shape of the frame, the required amount of light or orientation pattern, the number of semiconductor light emitting elements 10 required, the arrangement pattern, and the like. FIG. 12 shows an example of a light emitting device 100F in which a housing 20F is formed in a circular shape as an example. By setting it into a circular shape in this way, it becomes easy to adopt the structure which deform|transforms the said 2nd resin mold layer into a lens shape.

In addition, in the above examples, an example of a so-called COB (Chip On Board) type light emitting device in which the semiconductor light emitting element 10 is mounted on the base body 50 has been described. However, the present invention is not limited to the above structure, and can also be applied to chip-type light emitting devices and the like.

(Manufacturing method of light emitting device 100 )

Next, a method of manufacturing the light-emitting device 100 according to Example 1 will be described with reference to FIGS. 4A to 4D . First, as shown in FIG. 4A, the semiconductor light emitting element 10 and the protective element 12 are mounted by forming a wiring pattern on a substrate 50 previously formed with a wiring pattern by printing or the like, and the semiconductor light emitting element 10 is surrounded by a The method is to form the first frame 21 with resin for the first frame body. It should be noted that either the mounting of the semiconductor light emitting element 10 or the formation of the first frame 21 may be performed first. For example, in the case of mounting a semiconductor light-emitting element in a high-temperature environment such as reflow, the semiconductor light-emitting element is mounted first, and then the first frame 21 is formed. broken state of affairs.

Next, in the hardened state of the first frame 21 , as shown in FIG. 4B , the first molding resin is filled into the sealing area SA inside the first frame 21 to form the first resin mold layer 31 . At this time, the first molding resin is filled to a height substantially equal to the height of the first frame 21 . Thereby, it is possible to avoid the problem that the first molding resin spreads on the inner surface of the first frame 21 caused by the influence of surface tension, and it is possible to adjust the thickness of the first resin molding layer 31 and the thickness of the first resin molding layer 31 formed thereon. The thickness of the second resin molded layer 32 is formed to be uniform, thereby avoiding occurrence of uneven hue. It should be noted that the wavelength converting member is mixed into the first molding resin. When the first mold resin is filled, the wavelength conversion member mixed inside settles due to its own weight, and the wavelength conversion layer 34 and the translucent resin layer 35 are formed on the first resin mold layer 31 .

Furthermore, after the first mold resin is cured to form the first resin mold layer 31 , the second frame 22 is formed as shown in FIG. 4C . The second frame 22 is to cover the area exposed on the base body 50 from the upper surface to the outer surface of the first frame 21, and the lower end of the inner surface of the second frame 22 is the junction of the lower end of the inner surface of the first frame 21 and the base body 50. The positions are stacked so as to be outside the frame body 20 . Thereby, the second molding resin can be laminated substantially continuously on the upper surface of the first resin molding layer 31 also at the interface between the first frame 21 and the second frame 22, and the second molding resin can The thickness of the formed second resin mold layer 32 is substantially uniform over the entire surface. Moreover, when the 1st frame 21 is covered with the 2nd frame 22, the protection element 12 is embedded in the 2nd frame 22 at the same time, and this protection element 12 is protected.

Finally, in the state where the resin for the second frame is cured, the second mold resin is filled into the sealing area SA inside the second frame 22 to form the second resin mold layer 32 . The second molding resin is filled to a height substantially equal to that of the second frame 22 , whereby a uniform film thickness avoiding surface tension is also achieved. In addition, the second molding resin is mixed with a diffusing material, so that the emitted light of the semiconductor light emitting element 10 emitted from the first resin molding layer 31 and the wavelength-converted light converted by the wavelength converting member are diffusely reflected by the diffusing material. and diffuse, and emit light in a planar form from the sealing area SA in a state of uniform color mixing. When the mold resin is cured in this state to form the second resin mold layer 32, the light emitting device 100 in which the semiconductor light emitting element 10 is sealed by the sealing area SA can be obtained. In addition, the thicknesses of the first resin molded layer 31 and the second resin molded layer 32 are formed to be substantially uniform over the entire surface, and it is possible to obtain a high-quality, high-quality resin that suppresses color unevenness of the output light in the vicinity of the housing 20 . Quality glow.

As described above, according to the present embodiment, the sealing resin is separated into the first resin mold layer for performing wavelength conversion by compounding wavelength conversion members such as phosphor 36 and the second resin for reducing uneven light emission by compounding a diffusing material. The molding layer can obtain a light-emitting device with higher light quality.

A light-emitting device using an LED can have a structure in which an LED element 910 is mounted in a package 950 as shown in the cross-sectional view of FIG. 14 . In such a structure, in order to form the mold resin 930 into two layers, the first resin mold layer 931 including the phosphor 36 is first molded. Thereby, light emitted from the LED element 910 and fluorescence obtained by wavelength conversion of the emitted light as excitation light by the phosphor 36 can be generated in the first resin mold layer 931 . Next, the upper surface of the first resin molded layer 931 is filled with a second resin molded layer 932 containing a diffusion material. Accordingly, the emitted light from the LED element 910 and the fluorescence obtained by converting the emitted light from the wavelength of the phosphor 36 can be diffused in the second resin mold layer 932 , thereby obtaining uniform light.

However, in forming such a molded resin 930 in a two-stage structure, there is a problem that color unevenness occurs particularly in the vicinity of the frame body 920 . That is, as shown in the enlarged cross-sectional view of FIG. 15 in which the region indicated by the dotted line in FIG. in an ascending state. When the second resin molded layer 932 is molded thereon, the first resin molded layer 931 is necessarily thick and the second resin molded layer 932 is thinned in a portion of the frame body 920 . That is, the ratio R (= d ₁ /d ₂ ) of the thickness d ₁ of the first resin molded layer 931 to the thickness d ₂ of the second resin molded layer 932 at the central portion of the sealing area SA, The ratio R' of the thickness d _{1 ′} of the first resin molded layer 931 to the thickness d ₂ ′ of the second resin molded layer 932 varies. As a result, color unevenness occurs in the light emitted from the central portion of the sealing area SA and the light emitted from the edge portions.

On the other hand, in the light-emitting device according to this embodiment, as described above, the second frame is formed after forming the first resin mold layer for wavelength conversion by mixing wavelength conversion members such as phosphor 36, and the mixing diffusion layer is formed. The material is used to reduce the second resin molding layer of uneven light emission, so that a light emitting device with higher light quality can be obtained.

In addition, when the sealing material is provided in two layers in a resin molded package, a laminated ceramic package, etc., the positions of the ends of the first layer and the second layer must be structurally separated by a certain distance or more in order to avoid the above-mentioned surface tension. In this case, since the diameter of light emission is enlarged compared with the case of sealing with only the first layer, the light emitted from the light emitting element is scattered, causing a decrease in luminosity.

In contrast, in this embodiment, since the second frame is formed after the hardening of the first frame and the first molding resin, the ends of the frames of the first layer and the second layer can be joined together without expanding the frame. In the case of the size of the light emitting part, the sealing material is formed in two separate layers.

In addition, the wavelength conversion member such as a phosphor is not necessarily limited to the configuration arranged only on the first resin mold layer. For example, as the first resin molded layer, it is sealed with a sealing material of the first molding resin prepared with a white filler, and the second resin molded layer is sealed with a sealing material of the second molded resin prepared with phosphors such as YAG, for example. This makes it possible to obtain a high-brightness white light source. This structure is particularly effective for luminaires that mainly use the front light of the light emitting device.

(Example 2)

In the above examples, a two-layer structure has been described, but the present invention is not limited to two layers, and a multi-layer structure of three or more layers may be employed. Such an example is shown in FIG. 13 as a light emitting device 200 according to the second embodiment. In the example of the light-emitting device 200 shown in the figure, the resin mold layer 230 formed on the base body 250 is shown as a first resin mold layer 231, a second resin mold layer 232, a third resin mold layer An example of the three-layer structure of the system layer 233. That is, the frame body 220 is composed of the third frame 223 in addition to the first frame 221 and the second frame 222 . In addition, before molding each molded resin, the frame body 220 is raised and reinforced to the filling position of each molded resin. The height is approximately the same as the upper end of the frame body 220, and each resin mold layer can suppress the upward extension of the mold resin on the inner surface of the frame body 220 due to surface tension, thereby obtaining a high-quality light emitting device. As an example of such a multilayer structure, it is applicable to, for example, a structure in which a phosphor layer is a multilayer structure. That is, instead of mixing the phosphors in the same layer seamlessly, they are separated and laminated for each layer, thereby improving excitation efficiency using the absorption spectrum and reflection spectrum characteristics of the phosphors, etc. can be expected.

Furthermore, it is also possible to reduce the difference in refractive index between the resin molded layers. For example, when a semiconductor light-emitting element is flip-chip mounted, the emitted light is output through a production substrate (such as a sapphire substrate) that generates a semiconductor layer when manufacturing a semiconductor light-emitting element. There is a difference in the refractive index of the atmosphere. When light passes through media with different refractive indices, total reflection occurs at the interface, which lowers the efficiency of light extraction from the light emitting device. In contrast, by changing the refractive index difference in the path through which light passes through the resin mold layer stepwise from the sapphire substrate through the resin mold layer to the outside of the light-emitting device (atmosphere), total reflection at each interface can be suppressed. , so that an improvement in light extraction efficiency can be expected. For example, between the refractive index of the sapphire substrate of 1.75 and the refractive index of the atmosphere of 1, the refractive index is gradually reduced by using three resin mold layers such as 1.6→1.5→1.4, thereby suppressing total reflection at each interface, and finally An effect of increasing the amount of light that can be extracted from the light emitting device can be expected.

Furthermore, the resin mold layer may contain a wavelength-blocking/transmitting layer as a band-stop/band-pass filter for cutting or passing a specific wavelength component in the output light. For example, in applications where a light-emitting device is used as an illumination light source that cuts light of a specific wavelength in order to see a clean skin color, the resin mold layer may be provided with such a wavelength range blocking function, or such a layer may be added.

In this way, when the resin molded layer is not limited to two layers but has a multilayer structure having various functions, the present invention can be effectively utilized to form a uniform film thickness at the edge of each layer. Besides, in the resin molded layer formed in the multilayer structure as described above, the upper surface may not only be made a flat surface, but may also be deformed into a convex shape, a concave shape, or the like.

The light-emitting device and its manufacturing method according to the present invention can be used not only in semiconductors such as LEDs and laser elements used in lighting sources, LED displays, backlights, signals, illuminated switches, various sensors, and various indicators. Among light-emitting elements, it can also be widely used in the manufacture of semiconductor light-emitting elements.

It should be appreciated by those skilled in the art that while various preferred embodiments of the present invention have been illustrated and described, it is contemplated that the invention is not limited to the specific embodiments disclosed, which are considered to be The inventive concept is merely illustrated and should not be read as limiting the scope of the invention, and the particular embodiments disclosed apply to all modifications and changes which fall within the scope of the invention as defined in the appended claims. This application is based on application No. 2012-160043 filed in Japan on January 18, 2013, the contents of which are hereby incorporated by reference.

Description of reference symbols

100, 100B, 100C, 100D, 100E, 100F, 200…light emitting device

10...semiconductor light emitting element

12...Protective elements

14...External connection terminal

20, 20C, 20E, 220... frame body; 21, 21C, 21E, 221... first frame

22, 22C, 22E, 20F, 222... the second frame; 223... the third frame

30, 230…resin molded layer

31, 31C, 231...First resin molded layer

32, 32D, 232...Second resin molded layer

233...third resin molded layer

34, 34C...Wavelength conversion layer

35, 35C...Translucent resin layer

36… Phosphor

50, 250...Matrix

720…Resin

750…substrate

910…LED components

920…frame

930…molding resin

931...first resin molded layer

932...Second resin molded layer

950…substrate

SA… sealed area

GP...Gap

CP...near the frame

Claims (17)

1. A lighting device (100), comprising: matrix(50); a semiconductor light emitting element (10) mounted on the substrate (50); a frame (20) surrounding the semiconductor light emitting element (10) on the base (50); the resin molded layer (30) filled in the frame (20), The light emitting device (100) is characterized in that, The frame body (20) includes: a first frame (21); a second frame (22) formed on the upper surface of the first frame (21), The resin molded layer (30) includes: A first resin molded layer (31), which is formed at a height approximately equal to the top of the first frame (21), and embedded with the semiconductor light emitting element (10); a second resin molded layer (32) laminated on the upper surface of the first resin molded layer (31) and formed at a height substantially equal to the top of the second frame (22), At least one of the first resin molded layer (31) or the second resin molded layer (32) contains a device for converting the wavelength of the emitted light emitted by the semiconductor light emitting element (10). wavelength conversion member (36), The second frame (22) covers the upper surface and the outer surface of the first frame (21), The second frame (22) is thicker than the first frame (21) in plan view. 2. The light emitting device (100) according to claim 1, characterized in that, The base (50) has an insulating plane, a conductive member is formed on the insulating plane, And the conductive member is electrically connected to the semiconductor light emitting element (10). 3. The light emitting device (100) according to claim 1, characterized in that, The second resin molding layer (32) includes a diffusing material for diffusing the emitted light emitted by the semiconductor light emitting element (10). 4. The light emitting device (100) according to claim 1, characterized in that, The junction position between the lower end of the inner surface of the first frame (21) and the base body (50) is arranged on the inner side of the frame body (20) than the lower end of the inner surface of the second frame (22) . 5. The light emitting device (100) according to claim 1, characterized in that, The second frame (22) partially covers the end edges of the first frame (21) and the first resin molding layer (31). 6. The light emitting device (100) according to claim 5, characterized in that, disposing the lower end position (x ₂ ) of the inner surface of the second frame (22) at the junction with the first resin molded layer (31) at the opening end of the first frame (21) The position (x ₃ ) of the part is close to the inner side of the frame (20). 7. The light emitting device (100) according to claim 1, characterized in that, further comprising a protection element (12) connected in antiparallel to the semiconductor light emitting element (10), The protection element (12) is buried by the second frame (22). 8. The light emitting device (100) according to claim 1, characterized in that, The height of the central region of the second resin molded layer (32) is formed to be substantially the same height as the top of the second frame (22). 9. The light emitting device (100) according to claim 1, characterized in that, The height of the central area of the second resin molded layer (32) is formed higher than the top of the second frame (22). 10. The light emitting device (100) according to claim 1, characterized in that, The wavelength conversion member (36) is a phosphor (36) that can be excited by the light emitted by the semiconductor light emitting element (10), The first resin molding layer (31) includes: a phosphor layer (34); and a translucent resin layer (35) formed on the phosphor layer (34). 11. The light emitting device (100) according to claim 1, characterized in that, The light emitting device (100) includes a plurality of the semiconductor light emitting elements (10). 12. The light emitting device (100) according to claim 1, characterized in that, A plurality of the semiconductor light emitting elements (10) are arranged in a matrix. 13. The light emitting device (100) according to claim 1, characterized in that, The semiconductor light emitting element (10) is flip-chip mounted. 14. A method for manufacturing a light emitting device (100), the light emitting device (100) comprising: matrix(50); a semiconductor light emitting element (10) mounted on the substrate (50); a frame (20) surrounding the semiconductor light emitting element (10) on the base (50); a resin molded layer (30) filled in the sealed area defined by the frame (20), The manufacturing method of the light emitting device (100) is characterized by comprising: A step of forming a first frame (21) on the substrate (50); In the sealing area inside the first frame (21), the first molding resin is filled to the height of the first molding resin so as to seal the semiconductor light emitting element (10) installed in the sealing area. a process substantially in line with the top of the first frame (21); After the first molding resin is hardened to form a first resin molding layer (31), the second frame (22) is made to cover at least a part of the first frame (21). A frame (21) is exposed from the upper surface to the outer surface on the base (50), and the lower end of the inner surface of the second frame (22) is the same as the inner surface of the first frame (21). The process of stacking in such a way that the lower end of the base body (50) is outside the frame body (20) compared to the boundary position of the base body (50); Filling the second molding resin inside the second frame (22) so that the height of the second molding resin roughly coincides with the top of the second frame (22); A step of curing the second molding resin to form a second resin molding layer (32). 15. The manufacturing method of the light emitting device (100) according to claim 14, characterized in that, The first frame body resin forming the first frame (21) has a higher viscosity than the second frame body resin forming the second frame (22). 16. A method for manufacturing a light emitting device (100), characterized in that it comprises: A step of preparing a substrate (50) in which a conductive member is arranged on an insulating plane; a step of installing a semiconductor light emitting element (10) on the substrate (50) in a manner of being electrically connected to the conductive member, and forming a first frame (21) around the semiconductor light emitting element (10); A step of forming a first resin molded layer (31) in an area demarcated by the first frame (21); On the upper surface of the first frame (21), make the second frame (22) to cover the area exposed on the base (50) from the upper surface to the outer surface of the first frame (21), and The lower end of the inner surface of the second frame (22) is outside the frame body (20) than the boundary position between the lower end of the inner surface of the first frame (21) and the base (50). Carry out the process of stacking; A step of forming a second resin molded layer (32) in the area defined by the second frame (22). 17. The manufacturing method of the light emitting device (100) according to claim 16, characterized in that, The first frame body resin forming the first frame (21) has a higher viscosity than the second frame body resin forming the second frame (22).